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Monday, November 23, 2009

Tech Virtualization traps

Whenever an organisation looks into Virtualisation the cost savings is immediately pointed to as something that will just happen. This article points out many of the potential pitfalls or unexpected costs that can erode these benefits. Below I address some of the main issues in a virtual consolidation project.

The main reasons are from some assumptions that your current IT systems are capable of handling the new infrastructure. This is not always the case for a variety of reasons. However each of these reasons actually can give way to new cost benefit. These benefits can make the case for going virtual even better than before.

1. Unanticipated Management Overhead
Existing toolsets don't understand virtual technologies. The additional layer of complexity is something that doesn't get represented well by older tools. However this does mean that we can manage this layer though and get added benefits. It can be advantageous to be able to map virtual systems to the hardware - so that you can find the physical box, minimise licenses, balance resources so that there is less waste in the overall system.

2. Running more hardware than you need

Many organisations building virtual clusters make them huge and future proof. Each individual physical system is overspecified and has lots of redundant capacity as organisations will overbuild systems to ensure that they handle the migration. There is an element of uncertainty in the migration process and every organisation has different needs.

To avoid this, ensure that you accurately measure the use of existing systems before migration and in the pilot phase of the rollout validate these needs on the new systems. It could be that the overall requirement is less that expected, leading to larger cost savings.

3. Licensing Bloat

Licensing virtual systems actually gives some benefits. Many vendors such as Microsoft have improved licensing usage rights that take into account virtual systems running on a host. However there are some vendors that have less than beneficial licensing metrics. Watch out for situations where you might need to license the whole physical server if you have an application running on a virtual server. Isolate these to single servers or keep them physical.

Also, get a license management or software asset management system that can keep track of virtual systems and calculating the best license metrics.

4. Virtual System Sprawl

It is very easy to create a new virtual server. Much easier than a physical server. Instead of having to buy hardware, find rackspace to store it, get your infrastructure team to build the OS and install your applications, all you need to do is copy a folder of files and click start inside your management tool. This can lead to unauthorised or unplanned servers turning up in your network. Avoid this by having the same strict levels of process around the commissioning of the servers in the first place. Don't allow IT staff to just build another server unless there is a process around it.

Extra servers just waste your resources and cost you extra money in unneeded licenses, new systems and management.

5. Inadequate storage

In a large VM environment (or even a small one) a large amount of central storage is needed. To optimise this, the best way is usually through a SAN linked to the Host servers. Not all SANs are born equal however, and many new SANs support Virtual Server in better ways, recognising duplicate data to make better use of the storage. So commissioning a new SAN to specifically support the Virtual systems may be the smartest idea and optimise the performance and data requirements from the system.